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K Isobe

Publications and source records attributed to K Isobe.

At least 109 records · Page 6Linked to original sources
PubMed1999

Expression of Cell Cycle Regulating Proteins in an Unusual Transformation of Mantle Cell Lymphoma.

We describe here two patients with mantle cell lymphoma (MCL) who after a few years, developed to the diffuse large cell lymphoma (DLCL)( anaplastic centrocytic lymphoma) growing in a diffuse sheets without the classical MCL component. In both the initial and second biopsy specimens, in each case, tumor cells were positive for cyclin D1, sIgM, sIgD, and CD5, but were negative for CD10 and CD23. In a study of immunoglobulin heavy chain (IgH) gene rearrangement, using the polymerase chain reaction (PCR) method, the products obtained from each paired biopsy tissue sample were the same size, and in one case had an identical sequence to the non-mutated VH gene. Immunohistochemistry was used to examine the expression of p53, p27(Kip1) and cyclin E. Interestingly, there was clear overexpression of p53 protein in case 1 but not in case 2, compared with other typical MCL cases. The expression of p27(Kip1) in the second biopsies of each case was decreased compared with those in the initial biopsies. In case 2, however, p27(Kip1) was clearly expressed in the first and second biopsies, in contrast to other typical MCL cases. Thus these 2 cases demonstrate not only that the variant form of MCL may arise de novo, but also that MCL may transform to DLCL at the time of relapse. Although the mechanism of tumor progression/transformation is still poorly understood, the overexpression of p53 or p27(Kip1) may be linked to a cellular mechanism involved in the development of the variant form of MCL.

Journal Article↗
PubMed1999

Radiotherapy for large hepatocellular carcinoma combined with transcatheter arterial embolization and percutaneous ethanol injection therapy.

This study was performed to determine the effect of radiotherapy (RT) combined with transcatheter arterial embolization (TAE) and percutaneous ethanol injection (PEI) on large HCC. Between 1988 and 1996, 102 patients with unresectable, biopsy proven HCC underwent uniform pretreatment assessment followed by TAE and PEI. Of the 102 patients, 68 (67%) had more than 2 lesions in the liver, and the largest tumor sizes in each patient ranged from 3 to 8 cm in diameter. Immediately after TAE and PEI, external beam RT (36 to 70 Gy) was administered to the largest tumors only in 44 patients. The cause-specific 5-year survival rate for all patients was 39.9%. The 3-year survival rate of the RT group was better than that of the no RT group (81.1% vs. 54.6%). The cumulative local control rates of the largest treated tumors were 53.2% in the RT group and 32.7% in the no RT, respectively (p=0.006). When the survival rate was compared between patients with and without local control in the RT group, that of patients with local control was significantly better than that with local recurrences (p=0.048). No deaths or major treatment related complications occurred. RT combined with TAE and PEI did not clearly show improvement of the survival, however, it effectively controlled large HCC, and demonstrated minimal toxicity. This treatment may represent therapeutic option for some patients with unresectable large HCC.

Aged↗
PubMed1999

Expression of cell cycle regulating proteins in an unusual transformation of mantle cell lymphoma.

We describe here two patients with mantle cell lymphoma (MCL) who after a few years, developed to the diffuse large cell lymphoma (DLCL) (anaplastic centrocytic lymphoma) growing in a diffuse sheets without the classical MCL component. In both the initial and second biopsy specimens, in each case, tumor cells were positive for cyclin D1, sIgM, sIgD, and CD5, but were negative for CD10 and CD23. In a study of immunoglobulin heavy chain (IgH) gene rearrangement, using the polymerase chain reaction (PCR) method, the products obtained from each paired biopsy tissue sample were the same size, and in one case had an identical sequence to the non-mutated VH gene. Immunohistochemistry was used to examine the expression of p53, p27Kip1 and cyclin E. Interestingly, there was clear overexpression of p53 protein in case 1 but not in case 2, compared with other typical MCL cases. The expression of p27Kip1 in the second biopsies of each case was decreased compared with those in the initial biopsies. In case 2, however, p27Kip1 was clearly expressed in the first and second biopsies, in contrast to other typical MCL cases. Thus these 2 cases demonstrate not only that the variant form of MCL may arise de novo, but also that MCL may transform to DLCL at the time of relapse. Although the mechanism of tumor progression/transformation is still poorly understood, the overexpression of p53 or p27Kip1 may be linked to a cellular mechanism involved in the development of the variant form of MCL.

Cyclin E↗
PubMed1998

Elevated expression of PDI family proteins during differentiation of mouse F9 teratocarcinoma cells.

We investigated the expression of protein disulfide isomerase family proteins (PDI, ERp61, and ERp72) in mouse F9 teratocarcinoma cells during differentiation induced by treatment with retinoic acid and dibutyryl cAMP. Each member of this family was expressed at a constitutive level in undifferentiated F9 cells. During differentiation of F9 cells to parietal or visceral endodermal cells the protein level of all these enzymes increased, although the extent of this increase in both protein and mRNA levels varied among the enzymes. Certain proteins were found to be coimmunoprecipitated with PDI, ERp61, and ERp72 in the presence of a chemical crosslinker. Type IV collagen was significantly coprecipitated with PDI whereas laminin was equally coprecipitated with the three proteins. Furthermore, 210 kDa protein characteristically coprecipitated with ERp72. Thus, the induction of PDI family proteins during the differentiation of F9 cells and their association with different proteins may implicate specific functions of each member of this family despite the common redox activity capable of catalyzing the disulfide bond formation.

Animals↗
PubMed1998

Nuclear-recessive mutations of factors involved in mitochondrial translation are responsible for age-related respiration deficiency of human skin fibroblasts.

We addressed the question of whether both mitochondrial and cytoplasmic translation activities decreased simultaneously in human skin fibroblasts with the age of the donors and found that the age-related reduction was limited to mitochondrial translation. Then, to determine which genome, mitochondrial or nuclear, was responsible for this age-related, mitochondria-specific reduction, pure nuclear transfer was carried out from mitochondrial DNA (mtDNA)-less HeLa cells to four fibroblast lines, two from aged subjects, one from a fetus, and one from a patient with cardiomyopathy, and their nuclear hybrid clones were isolated. A normal fibroblast line from the fetus and a respiration-deficient fibroblast line from the patient were used as a positive and a negative control, respectively. Subsequently, the mitochondrial translation and respiration properties of the nuclear hybrid clones were compared. A negative control experiment showed that this procedure could be used to isolate even nuclear hybrids expressing overall mitochondrial respiration deficiency, whereas no respiration deficiencies were observed in any nuclear hybrids irrespective of whether their mtDNAs were exclusively derived from aged or fetal donors. These observations suggest that nuclear-recessive mutations of factors involved in mitochondrial translation but not mtDNA mutations are responsible for age-related respiration deficiency of human fibroblasts.

Aging↗
PubMed1998

New remote-controlled growing-rod spinal instrumentation possibly applicable for scoliosis in young children.

Progressive scoliosis in young children has been treated with "spinal instrumentation without fusion" to avoid interference with spinal growth. Patients have to undergo a series of operations to have instruments exchanged for maintaining the correction. We have developed a newly designed remote-controlled growing-rod spinal instrumentation system proposed for the treatment of progressive scoliosis in young children. It can be used to stretch and correct the spinal deformities repeatedly and non-surgically, by means of a remote controller, after the first instrumentation operation. The purpose of this study is to describe the possible clinical application of this system for the treatment of progressive scoliosis in young children. To this end, we used the system in five beagle dogs with induced scoliotic deformities. The maximum distraction force of the instrument was 194 N. Correction of 1 cm was performed non-surgically in awake animals 3 weeks after the instrumentation operation, and then correction of 1 cm was carried out again 6, 9, and 12 weeks after the operation. The average initial Cobb's angle of the induced scoliotic deformities was 25 degrees; this was corrected to 20 degrees, 15 degrees, 8 degrees, and 3 degrees, after the distractions at 3, 6, 9, and 12 weeks, respectively, postoperatively. All corrections were performed non-surgically without apparent complications. By repetitive distractions with the use of our new system, we may be able to reduce the number of operations required in young scoliotic children.

Animals↗
PubMed1998

Protection of xeno-hepatocytes from complement-mediated cytolysis by transduction with homologous restriction factor 20 gene using retroviral vector.

Xeno-hepatocyte transplantation has the possibility to substitute for clinical liver transplantation in certain restricted hepatic diseases such as inherited metabolic disorders. To overcome human complement-dependent cytotoxicity on xeno-hepatocytes, the effectiveness of ex vivo transfer with the homologous restriction factor 20 (HRF20, CD59) gene was examined on primary-cultured xeno-hepatocytes using a retroviral vector. Primary-cultured rat hepatocytes transduced with HRF20 cDNA expressed HRF20 antigen by flow cytometric analysis and showed the integration of HRF20 cDNA to the genomic DNA by the polymerase chain reaction. The viability of rat hepatocytes incubated with 50% human serum was decreased due to complement-dependent cytotoxicity, whereas that of the transfectant was significantly protected (77.2+/-9.4 vs. 97.8+/-5.2%, p < 0.01). It was concluded that primary-cultured xeno-hepatocytes transduced with HRF20 cDNA using a retroviral vector could escape complement-dependent cytolysis by human serum.

Animals↗
PubMed1998

Expression of mRNA coding for four catecholamine-synthesizing enzymes in human adrenal pheochromocytomas.

OBJECTIVE: To understand the molecular mechanisms by which catecholamine synthesis is controlled in pheochromocytomas--tumors that synthesize and release catecholamines, which are related to various clinical manifestations of the condition. METHODS: We measured the concentrations of mRNA coding for the catecholamine-synthesizing enzymes tyrosine hydroxylase, aromatic L-amino acid decarboxylase (AADC), dopamine beta-hydroxylase (DBH) and phenylethanolamine N-methyl transferase (PNMT) and for the catecholamine contents in 12 pheochromocytomas and 12 normal adrenal medullas. RESULTS: The mean content of total catecholamine and the beta-actin mRNA expression in the pheochromocytomas were almost the same as those in the normal adrenal medullas. However, the tyrosine hydroxylase, AADC and DBH mRNA concentrations in the pheochromocytomas were greater than those of the normal adrenal medullas. Conversely, the PNMT mRNA concentration in the pheochromocytomas was lower than that in the normal adrenal medullas. These differences are responsible for the difference in the proportions of catecholamines between pheochromocytomas and normal adrenal medullas. The constitutive expression of the catecholamine-synthesizing enzyme mRNAs varied in magnitude among the pheochromocytomas, and the tyrosine hydroxylase mRNA expressions correlated with the contents of total catecholamine in the tumors (r=0.964, P<0.0001). CONCLUSIONS: These findings indicate that catecholamine production in pheochromocytomas is primarily controlled by the level of gene expression.

Adrenal Gland Neoplasms↗
PubMed1998

Identification and initial characterization of stathmin by the differential display method in nerve growth factor-treated PC12 cells.

The differential display of mRNA is a new strategy to identify genes that are differentially expressed under altered conditions. We applied this method to determine differential gene expression in the rat pheochromocytoma cell line during differentiation induced by nerve growth factor (NGF). Three different mRNA species were isolated, and their differential expression was confirmed by RT-PCR. One of the mRNA species was identified as stathmin, a 19 kDa cytosolic protein attracting increasing interest for its role in signal transduction. In the NGF-treated PC12 cells, the expression of stathmin mRNA increased in a time-dependent manner, as assessed by northern blot analysis and RT-PCR. We also assessed by northern blot analysis how the expression of stathmin mRNA was altered in human pheochromocytomas (n = 5) compared with that in normal adrenal medulla tissue (n = 5). The mRNA concentrations were found to be significantly greater in the pheochromocytomas than in the normal tissues. It has been shown that stathmin mRNA concentrations are increased in various tumor cells. As pheochromocytomas are well-differentiated tumors of neural origin, it is not unexpected that stathmin mRNA is overexpressed in these tumors. Stathmin was isolated and identified as a differentially expressed gene by the differential display method in PC12 cells during differentiation induced by NGF. In addition, stathmin mRNA was found to be overexpressed in human pheochromocytomas. The mechanisms responsible for the up-regulation of stathmin mRNA during differentiation of PC12 cells and the significance of its overexpression in human pheochromocytomas remain to be determined.

Adrenal Gland Neoplasms↗
PubMed1998

Advanced nasopharyngeal carcinoma treated with chemotherapy and radiotherapy: distant metastasis and local recurrence.

One hundred and twenty-nine patients with NPC treated at the Department of Radiology, Chiba University Hospital and Keio University Hospital from 1980 through 1993 were selected for this study. Forty-four patients received cisplatin (CDDP)- or carboplatin-based chemotherapy, and 58 patients received adriamycin (ADM)- and/or 5-FU-based chemotherapy. The remaining 27 patients were treated with radiotherapy alone. The median radiation dose to the nasopharyngeal region was 64 Gy, and to the initially involved cervical node, 60 Gy. The 5 year survival rates for the CDDP, the ADM/5-FU and the radiation alone groups were 61%, 47% and 42%, respectively. The cumulative incidences of local control in the CDDP, the ADM/5-FU and the radiation alone groups were 77%, 49% and 53% respectively. The CDDP group achieved the significantly better local control (CDDP vs ADM: p=0.001). The overall incidence of distant metastases was 54% in the CDDP group. On the other hand, it was 24% in the ADM/5-FU group and 22% in the radiation alone group (CDDP vs ADM: p=0.048). While the locoregional control rate was significantly better in the CDDP given group, more distant metastases were seen in this group.

Adolescent↗
PubMed1998

Nitric oxide: a possible etiologic factor in spinal cord cavitation.

To determine whether nitric oxide (NO) is related to spinal cord cavitation, we treated mice that underwent spinal cord injury with NG-mono-methyl-L-arginine (N-MMA). Spinal cord specimens were subjected to glial fibrillary acidic protein (GFAP) immunostaining, which is selective for astrocytes. Spinal cord cavities and GFAP-positive glial cells appeared simultaneously at 3 days after spinal cord injury, and the cavities enlarged at 7 days. In mice receiving N-MMA, the cavities were significantly smaller than those in the mice that underwent spinal cord injury only. However, the numbers of GFAP-positive cells showed no difference between these two groups. These experimental findings suggest that cavitation of the spinal cord is caused mainly by NO released from activated glial cells.

Animals↗
PubMed1998

[Bleomycin, adriamycin, cyclophosphamide, vincristine, deacadron, etoposide (BACOD-E) chemotherapy for the treatment of non-Hodgkin's lymphoma: long-term survival rate and complications].

This study was performed to analyze the effect of Bleomycin, Adriamycin, Cyclophosphamide, Vincristine, Deacadron, Etoposide (BACOD-E) chemotherapy for patients with non-Hodgkin's lymphoma. Seventy patients with non-Hodgkin's lymphoma (stage I: 15, stage II: 23, stage III: 20, and stage IV: 12) were treated at the Department of Radiology, Chiba University Hospital, between 1987 and 1995. The response rates for treatment were CR: 63%, PR: 35%, and PD: 2%. The overall disease-free 5-year survival rate was 54%, and those for each stage were as follows: stage I: 78%, stage II: 55%, stage III: 51%, and stage IV: 28%. There were no significant differences between patients with and without B symptoms, or those with and without elevated LDH levels. Treatment associated deaths occurred in six patients. Two patients died due to side effects of chemotherapy during treatment, and one patient due to leukemia 2 years and 5 months after treatment. One patient died due to radiation pneumonitis, one patient due to heart failure, and one patient due to an unknown reason one month after treatment. This chemotherapy may be useful for patients with advanced disease or unfavorable prognostic factors such as B symptoms or elevated LDH. Moreover, the addition of radiation therapy may prolong survival.

Adolescent↗
PubMed1997

Isolation and characterization of mitochondrial DNA-less lines from various mammalian cell lines by application of an anticancer drug, ditercalinium.

Since ethidium bromide was not effective in mouse cell lines for isolating mitochondrial DNA (mtDNA)-less cells (rho zero cells), we examined whether an anticancer drug, ditercalinium (DC), which has been shown to exclude mtDNA from mouse cell lines, could be effective in various mouse and human cell lines. We found that after DC treatment rho zero cells could be isolated from all cell lines of mouse or human origin tested. Moreover, these rho zero cells maintained ability to receive exogenously imported mtDNA and allow its replication and gene expression. These observations suggest that DC eliminates mtDNA from mouse and human cells without affecting the property to receive exogenous mtDNA. Therefore, DC could be applicable to cell lines expressing various differentiated phenotypes for studying whether mtDNA plays a significant role in expression of phenotypes by manipulating mtDNA elimination and reintroduction.

3T3 Cells↗
PubMed1997

In vitro and in vivo expression of inducible nitric oxide synthase during experimental endotoxemia: involvement of other cytokines.

In this study, we investigated the expression of genes for inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6) of Kupffer cells in the presence of lipopolysaccharide (LPS), and the tissue expression of iNOS in a rat liver after LPS injection at various time intervals. The effects of L-NG-nitroarginine-methyl-esther HCI (L-NAME), a NO inhibitor, also were examined. The mRNA transcripts of TNF-alpha, IL-1 beta, and IL-6 were rapidly detected no more than at 1 h after LPS stimulation, whereas the iNOS transcript was detectable from 3 h after LPS stimulation and maximally increased at 12 h. This fact suggested that these early induced cytokines were related to expression of iNOS. Using an anti-iNOS antiserum raised against recombinant iNOS protein, immunohistochemical analysis was made to reveal kinetics of NO producing cells. The cells immunoreactive for iNOS appeared at 6 h post-LPS injection in the sinusoids of the liver. By structural and immunohistochemical studies, almost all iNOS positive cells were identified as Kupffer cells and endothelial cells. The number of cells immunoreactive for iNOS increased until 12 h post-LPS injection. At 24 h after LPS injection, iNOS positive cells were restricted to the foci of spotty necrosis. Hepatic injury measured by released enzymes was increased by pretreatment of L-NAME before LPS injection.

Animals↗
PubMed1997

Identification of inheritance modes of mitochondrial diseases by introduction of pure nuclei from mtDNA-less HeLa cells to patient-derived fibroblasts.

A nuclear genome delivery system was developed to deduce the modes of inheritance of the clinical phenotypes observed in patients with mitochondrial diseases by transfer of pure nuclei from normal cells to fibroblasts from the patients. The problem of possible contamination of the nuclei with a small amount of mtDNA was overcome by using mtDNA-less (rho0) human cells as nuclear donors. In this study, intercellular transfer of pure nuclei was carried out by simple fusion of rho0 HeLa cells with 533 fibroblasts from a patient with a fatal mitochondrial disease, which were deficient in cytochrome c oxidase and succinate dehydrogenase activities. The results showed that the cytochrome c oxidase and succinate dehydrogenase activities were restored by the introduction of pure HeLa nuclei, suggesting that the observed phenotypes of mitochondrial dysfunction were not due to mtDNA mutations but to nuclear, recessive mutations. Thus, our nuclear transfer system is effective for determining whether a mitochondrial or nuclear genome of a patient is responsible for a disease and whether deficiency of mitochondrial enzymes, including enzymes exclusively encoded by nuclear genomes, is transmitted in a nuclear recessive or nuclear dominant way, providing the parents of the patients with valuable information for genetic counseling on the risk of mitochondrial diseases in their next babies.

Adenosine Triphosphatases↗